1) Field of the Invention
The present invention relates generally to devices for carrying items, and, more specifically, to an ergonomically improved tote with handles.
2) Related Art
In many areas of industry, such as in manufacturing, processing or parts distribution, objects must be gathered or stored and moved by hand from one location to another in containers such as boxes, tubs or trays. A typical container often has a rolled top edge or similar structure which requires the fingers to lift and carry the load with no help from the thumb. The finger tips have only about twenty-five to thirty percent of the strength of the full hand, and therefore containers which rely on finger tip lift cause excessive stress and limit the amount of weight that can be safely lifted or carried.
Other types of containers which have hand cutouts on the side provide better use of full hand strength for lifting and carrying. However, as these types of containers are lifted, the wrist bends rather than remains straight. Bending of the wrist results in high physical stress, reduced hand strength, and reduced hand and eye coordination. Additional problems with cutouts include lack of clearance for easy insertion of a gloved hand and the relatively small contact area between the hand and the thin upper portion of the cutout which results in the topside of the handle cutting into the hand. The sharper the carrying edge that contacts the hand, the less load the hand can support.
Some containers include handles that require the hands to be spread widely during lifting and carrying. Large tray length with the resultant increased hand spread place more of the load on weaker muscles of the shoulder rather than on the strong bicep muscles and limits the load that can comfortably be carried.
Container width (front to back distance) directly influences load center of gravity. Many of the wider containers of the prior art cause more low back stress as the center of gravity moves forward.